For the switch I’d just use a normal panel mount ON-ON mini (not sub-mini) toggle and use some old clipped resistor leads to connect it to the pcb. I’m pretty sure I used the substitution you mentioned for my first one or two Cadets, but it’s not a perfect fit… The legs are a tiny bit too short, so you have to put the switch in at a not exactly perpendicular angle to the front panel. It’s not a huge deal, and I’m not going to change mine, but on all the other Cadets and Castles I’ve built so far, I’ve just been using panel mount switches and I feel much better about it.

Example I saved from someone’s facebook post a while ago of how to do it with a panel mount switch (sorry forgot whose post!):

The capacitor substitutions sound fine to me. The things to match when it comes to capacitors is value (obviously), general type (electrolytic vs MLCC), voltage, tolerance, lead spacing, and you might as well match the dielectric too. Looks like you got that right in all those cases.

And if those restrictions are too tight to find a substitution, the voltage, tolerance, lead spacing, and dielectric don’t always have to exactly match the spec’d part, they just need to be good enough, but knowing when they are often requires a bit of understanding the circuit:

Most eurorack circuits will never deal with a voltage swing bigger than +12V to -12V (so 24V total) and often the way the capacitors are used in the circuits they’re not seeing that max swing, so often 25V or even 16V caps can be used, but not always.

Tolerance of caps is like tolerance of resistors… higher tolerance is nicer but not always necessary depending on what it’s purpose is (though in video accurate caps matter a bit more than audio).

Lead spacing won’t affect the way the circuit works at all (unless the spacing causes you to have really long leads), but it’s nice to not have to bend some 5mm-spaced leads to fit into 2.5mm-spaced holes and vice versa.

And the dielectric doesn’t always matter either, though sometimes you don’t have much choice for a desired capacitance and tolerance and voltage combo.

always try to buy as much as possible from the same supplier as possible - and from as few suppliers as possible - to reduce postage - so I’d either buy from mouser or digikey unless you can help it

substitutes for the capacitors at mouser - there seems to be an improved susbtitute finder at mouser - if you scroll down a bit you can tick what you need from the present spec and these just showed up first in the list and look ok to me